docs: filesystems: convert gfs2-uevents.txt to ReST

This document is almost in ReST format: all it needs is to have
the titles adjusted and add a SPDX header. In other words:

- Add a SPDX header;
- Add a document title;
- Adjust section titles;
- Add it to filesystems/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Link: https://lore.kernel.org/r/1d1c46b7e86bd0a18d9abbea0de0bc2be84e5e2b.1581955849.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 100 deletions

diff --git a/Documentation/filesystems/gfs2-uevents.txt b/Documentation/filesystems/gfs2-uevents.txt
deleted file mode 100644
index 19a19ebebc34..000000000000
--- a/Documentation/filesystems/gfs2-uevents.txt
+++ /dev/null
@@ -1,100 +0,0 @@
-                              uevents and GFS2
-                             ==================
-
-During the lifetime of a GFS2 mount, a number of uevents are generated.
-This document explains what the events are and what they are used
-for (by gfs_controld in gfs2-utils).
-
-A list of GFS2 uevents
------------------------
-
-1. ADD
-
-The ADD event occurs at mount time. It will always be the first
-uevent generated by the newly created filesystem. If the mount
-is successful, an ONLINE uevent will follow.  If it is not successful
-then a REMOVE uevent will follow.
-
-The ADD uevent has two environment variables: SPECTATOR=[0|1]
-and RDONLY=[0|1] that specify the spectator status (a read-only mount
-with no journal assigned), and read-only (with journal assigned) status
-of the filesystem respectively.
-
-2. ONLINE
-
-The ONLINE uevent is generated after a successful mount or remount. It
-has the same environment variables as the ADD uevent. The ONLINE
-uevent, along with the two environment variables for spectator and
-RDONLY are a relatively recent addition (2.6.32-rc+) and will not
-be generated by older kernels.
-
-3. CHANGE
-
-The CHANGE uevent is used in two places. One is when reporting the
-successful mount of the filesystem by the first node (FIRSTMOUNT=Done).
-This is used as a signal by gfs_controld that it is then ok for other
-nodes in the cluster to mount the filesystem.
-
-The other CHANGE uevent is used to inform of the completion
-of journal recovery for one of the filesystems journals. It has
-two environment variables, JID= which specifies the journal id which
-has just been recovered, and RECOVERY=[Done|Failed] to indicate the
-success (or otherwise) of the operation. These uevents are generated
-for every journal recovered, whether it is during the initial mount
-process or as the result of gfs_controld requesting a specific journal
-recovery via the /sys/fs/gfs2/<fsname>/lock_module/recovery file.
-
-Because the CHANGE uevent was used (in early versions of gfs_controld)
-without checking the environment variables to discover the state, we
-cannot add any more functions to it without running the risk of
-someone using an older version of the user tools and breaking their
-cluster. For this reason the ONLINE uevent was used when adding a new
-uevent for a successful mount or remount.
-
-4. OFFLINE
-
-The OFFLINE uevent is only generated due to filesystem errors and is used
-as part of the "withdraw" mechanism. Currently this doesn't give any
-information about what the error is, which is something that needs to
-be fixed.
-
-5. REMOVE
-
-The REMOVE uevent is generated at the end of an unsuccessful mount
-or at the end of a umount of the filesystem. All REMOVE uevents will
-have been preceded by at least an ADD uevent for the same filesystem,
-and unlike the other uevents is generated automatically by the kernel's
-kobject subsystem.
-
-
-Information common to all GFS2 uevents (uevent environment variables)
-----------------------------------------------------------------------
-
-1. LOCKTABLE=
-
-The LOCKTABLE is a string, as supplied on the mount command
-line (locktable=) or via fstab. It is used as a filesystem label
-as well as providing the information for a lock_dlm mount to be
-able to join the cluster.
-
-2. LOCKPROTO=
-
-The LOCKPROTO is a string, and its value depends on what is set
-on the mount command line, or via fstab. It will be either
-lock_nolock or lock_dlm. In the future other lock managers
-may be supported.
-
-3. JOURNALID=
-
-If a journal is in use by the filesystem (journals are not
-assigned for spectator mounts) then this will give the
-numeric journal id in all GFS2 uevents.
-
-4. UUID=
-
-With recent versions of gfs2-utils, mkfs.gfs2 writes a UUID
-into the filesystem superblock. If it exists, this will
-be included in every uevent relating to the filesystem.
-
-
-